Re:Intel Issues Updates to Protect Systems from Security Exp...
by pas on Thursday January 04, 2018 @04:04PM
(#16074065)
How do you know this?
I think it's worth noting that it's entirely possible, that if you are a CPU execution pipeline designer that you think about memory loads/stores, L1 cache, branch prediction and speculative execution, and it occurs to you that the cache gets polluted by spec exec, and the branches can be security checks.
But the solution is simple. If the branch is important, wait for it. (Load it into L1 cache before the branch - use a memory barrier.)
The fact that this is not in any ISA docs is a likely pointer toward the possibility that it in fact hadn't occurred to them.
These attacks are the same as any new invention. Easy to see once you've grasped the concept.
I think it's worth noting that it's entirely possible, that if you are a CPU execution pipeline designer that you think about memory loads/stores, L1 cache, branch prediction and speculative execution, and it occurs to you that the cache gets polluted by spec exec, and the branches can be security checks.
But the solution is simple. If the branch is important, wait for it. (Load it into L1 cache before the branch - use a memory barrier.)
The fact that this is not in any ISA docs is a likely pointer toward the possibility that it in fact hadn't occurred to them.
These attacks are the same as any new invention. Easy to see once you've grasped the concept.